The present invention relates to the field of cathode ray tube manufacture. More particularly, the present invention relates to storing a supply of cathode ray tube components, particularly funnels, for use in the cathode ray tube manufacturing process. The present invention provides a protective covering for maintaining the quality and integrity of cathode ray tube components while those components are in storage awaiting assembly.
Cathode ray tubes (xe2x80x9cCRTsxe2x80x9d) are used in most television sets and computer and video monitors. The CRT is a glass tube with a bottle-like shape in which a relatively flat bottom portion narrows into an elongated neck portion. (see, e.g., FIG. 1, 100). The relatively flat portion of the CRT becomes the screen on which the display of the television set or monitor is generated when the CRT is incorporated therein. Phosphor, a material that emits light when struck by an electron beam, is coated over the screen portion of the CRT.
An electron gun is then installed in the neck of the CRT. A stream of electrons emitted from the electron gun is scanned over the phosphor and turned on and off during the scanning to cause the phosphor to glow in certain places and not others. In very simple terms, this is how an image is generated on the screen of a television or video monitor.
A yoke is provided around the neck of the CRT. This yoke produces a changing magnetic field through which the electron beam from the electron gun passes. The electron beam is deflected by the magnetic field of the yoke. Consequently, by varying the magnetic field created by the yoke in a precise cycle, the electron beam can be scanned, line-by-line, over the entire surface of the screen to generate video images thereon.
It is very important to ensure that no dust or other contaminants are allowed into the CRT during manufacture, and particularly before and during the installation of the electron gun. Contaminants that remain in the CRT when the electron gun is operating can degrade the performance of the CRT and even cause damage to the tube.
Generally, the neck or funnel portion of the CRT is manufactured separately from the relatively flat display portion. The display portion is then attached to the funnel using molten glass known as frit. The frit cools and seals the display portion to the funnel to complete the tube. Obviously, great care must be taken before the funnel and display portions of the CRT are sealed together to ensure that no dust or other contaminants lodge on the components.
Additionally, it is important to keep the CRT components dry. In particular, moisture can degrade the quality of the final before the final is incorporated into a completed CRT.
While it is necessary to keep CRT funnels clean and dry before they are incorporated into a CRT, it has also been the practice in CRT manufacture to maintain a supply of funnels so that the CRT production line can be kept going even if the supply of funnels is temporarily interrupted. Having a supply of funnels as a buffer for the production line ensures that the production line will not have to stop or slow down if the supply of funnels is temporarily exhausted.
Obviously, however, the longer funnels are stored to support the production line, the more likely it is that the funnels will be damaged by moisture or contaminated by dust or other contaminants. Consequently, there is a need in the art for a means and method of protecting CRT components, particularly funnels, from contamination and moisture damage prior to being used to assemble a CRT in a production line.
The present invention meets the above-described needs and others. Specifically, the present invention provides a means and method of protecting CRT components, particularly funnels, from contamination and moisture damage prior to being used to assemble a CRT in a production line.
Additional advantages and novel features of the invention will be set forth in the description which follows or may be learned by those skilled in the art through reading these materials or practicing the invention. The advantages of the invention may be achieved through the means recited in the attached claims.
The present invention may be embodied and described as a protective covering for cathode ray tube components that have been stockpiled to support an assembly line. The protective covering preferably includes a protective cover sized to cover and provide a protected environment for the stockpile of a cathode ray tube component; and a fastener for fastening the protective cover in place over the stockpile of a cathode ray tube component. The cathode ray tube component being stockpiled may be a funnel.
The stockpile of the cathode ray tube component is preferably a rack on which a supply of the cathode ray tube component is stored. In such a case, the fastener may fasten the protective cover to the rack. The rack may be placed on a pallet or the supply of the cathode ray tube component may be placed on a pallet. In such a case, the fastener may fasten the protective cover to the pallet.
Preferably, the protective covering also provides a moisture-absorbent element for preventing moisture from damaging the stockpile of a cathode ray tube component. The moisture-absorbent element may be disposed in a number of pockets which are on an inside surface of the protective cover. Preferably, the moisture-absorbent element is a number of silica packs.
The present invention also encompasses the methods of making and using the protective covering described above. Specifically, the present invention encompasses a method of protecting cathode ray tube components that have been stockpiled to support an assembly line by covering the stockpile of a cathode ray tube component with a protective cover that is sized to cover and provide a protected environment for the stockpile of a cathode ray tube component. This method also preferably includes fastening the protective cover in place over the stockpile of a cathode ray tube component.